Twin-nibbed writing instrument



FIG. 1 is a left front perspective view of a twin-nibbed writing instrument showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and

FIG. 8 is a left front perspective view with one of the cap members in a stored position. 

The ornamental design for twin-nibbed writing instrument, as shown and described. 